1. Field
The presently disclosed subject matter relates to a lighting fixture unit.
2. Description of Related Art
As a lighting fixture unit to be used as a vehicle signal light or an agricultural light, a lighting fixture unit which emits light forward in a linear shape, as shown in Japanese Patent Application Laid-open Publication No. 2007-48470 (Patent Document 1) or Japanese Patent No. 4290601 (Patent Document 2), has been conventionally known.
A light fixture unit 800 of Patent Document 1 is equipped with: a light source 801 having a light intensity distribution in which light is dispersed in a right and left direction; an inner lens 802 which is elongated in the right and left direction and disposed at the front of the light source 801; and an outer lens 803, as shown in FIG. 5A. The light fixture unit 800 converts the right-left-direction dispersed light emitted from the light source 801 into parallel light along an optical axis of the light source 801 by the inner lens 802, and then diffuses the light by the outer lens 803 so that the outer lens 803 emits the light in a linear shape.
A light fixture unit 900 of Patent Document 2 is equipped with a light source 901 such as an LED, and a light guide body 902 which is elongated in the right and left direction and disposed at the front of the light source 901, as shown in FIG. 5B. The light guide body 902 includes a left-right pair of first reflection surfaces 902A, 902A which constitutes a form of paraboloid of revolution whose focal point is the light source 901 at a central region in a front surface of the light guide body 902. On both outsides of the first reflection surfaces 902A, 902A, output surfaces 902B, 902B each elongated in the right direction or in the left direction are formed. On the opposite side surfaces with respect to the output surfaces 902B, 902B, a plurality of second reflection surfaces 902C, . . . are formed. The light which is emitted from the light source 901 and enters into the light guide body 902 is reflected on the pair of first reflection surfaces 902A, 902A in the right direction or in the left direction, further reflected on the second reflection surfaces 902C, . . . forward, and diffused and emitted from the output surfaces 902B, 902B so that the output surfaces 902B, 902B emit light in a linear shape.
However, in the case of the light fixture unit 800 of Patent Document 1, the special light source 801 having the light intensity distribution in which light is dispersed in a right and left direction, and the two lenses (light guide bodies) of the inner lens 802 and the outer lens 803 are required. As a result, high costs are required.
Meanwhile, in the case of the light fixture unit 900 of Patent Document 2, though the special light source or two light guide bodies are not necessary, there is a problem that the first reflection surfaces 902A, 902A which do not emit light (emits no light) have large sizes in the right and left direction because the light emitted radially from the light source 901 enters directly into the light guide body 902 and then is reflected on the first reflection surfaces 902A, 902A having the form of paraboloid of revolution. As a result, a dark portion at a central region of the light fixture unit 900 becomes large when being seen from the front, and the light has difficulty in being recognized as having a linear shape.